Development and testing of a green fluorescent protein-based bacterial biosensor for measuring bioavailable arsenic in contaminated groundwater samples

• Published in: Environmental toxicology and chemistry 2005-07, Vol.24 (7), p.1624-1631
• Main Authors: Liao, Vivian Hsiu-Chuan, Ou, Kun-Lin
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Applied ecology; Aquifer Testing; Arsenic; Arsenic - pharmacokinetics; Bacterial biosensor; Base Sequence; Bioavailability; Bioavailable arsenic; Biological and medical sciences; Biological Availability; Biosensing Techniques; Biosensors; Contaminants; Contaminated groundwater; Contamination; DNA Primers; E coli; Ecotoxicology, biological effects of pollution; Environmental testing; Escherichia coli; Fundamental and applied biological sciences. Psychology; General aspects; Green fluorescent protein; Green Fluorescent Proteins - chemistry; Groundwater; Groundwater pollution; Kinetics; Plasmids; Sensitivity and Specificity; Staphylococcus aureus; Water analysis; Water Pollutants, Chemical - pharmacokinetics; Water sampling
• ISSN: 0730-7268; 1552-8618
• DOI: 10.1897/04-500R.1

A green fluorescent protein (GFP)‐based bacterial biosensor for the detection of bioavailable As(III), As(V), and Sb(III) was developed and characterized. The biosensor strain Escherichia coli DH5α (pVLAS1) was developed based on the expression of gfp under the control of the ars promoter and the arsR gene of Staphylococcus aureus plasmid pI258. Strain DH5α (pVLAS1) responded mainly to As(III), As(V), and Sb(III), with the lowest detectable concentrations being 0.4, 1, and 0.75 μM, respectively, during a 2‐h exposure and 0.1 μM for all three metal ions with an 8‐h induction period. To assess its applicability for analyzing environmentally relevant samples, the biosensor was field‐tested on shallow‐well groundwater for which contaminant levels were known. Our results demonstrate that the nonpathogenic bacterial biosensor developed in the present study is useful and applicable in determining the bioavailability of arsenic with high sensitivity in contaminated groundwater samples, and they suggest a potential for its inexpensive application in field‐ready tests.